Fifth Generation

In this generation the planetary drive shaft was improved. The star gear was supported on the edges. The cam lobes on the crankpin were improved. Also a new technique to make the cylinder walls was tried. The combustion chamber wall was made from nylon. The viewing window into the combustion chamber was enlarged to expose the transfer valve and its movement.

The throttle was driven by gears in generation 5.

The planetary crankshafts of generation 5 were parallel.

Each planetary crankshaft drove a pair of reciprocating combustion chambers.